1. Field of the Invention
The present invention is related to a nozzle head for a vacuum cleaner with a duster function, and more particularly to a nozzle head for a vacuum cleaner with a duster function which employs a roller-shaped duster member that is rotated at a predetermined angle in accordance with the moving direction of the nozzle head when required in order to use a larger cleaning surface of the duster member, thereby improving cleaning efficiency of the duster member, and which causes attachment and detachment of the duster member to be easy and separation of the duster member to be prevented during use, thereby providing the user with considerable convenience.
2. Description of the Prior Art
Referring to FIGS. 1 and 2, there is shown a conventional nozzle head for a vacuum cleaner. As shown in the drawings, the nozzle head comprises upper and lower casings 1 and 2, a ]-shaped frame 4 for fixing a flat duster 3 therein which is received in the upper and lower casings 1 and 2, a support plate 5 for pressing the duster 3 which is inserted in the frame 4 and mounted on the upper casing 1 by means of a screw 6, a pair of compression coil springs 7 and 7' interposed between the upper casing 1 and the frame 4, and a compression coil spring 7" disposed between the upper casing 1 and the support plate 5.
Note specifically stated, the upper casing 1 is formed with a pair of locking holes 8 at opposite ends. The locking holes 8 and 8' are provided at inner surfaces thereof With shoulders 9 and 9', respectively (see FIG. 2). The lower casing 2 is formed with an elongated rectangular hole 10 at its central portion. An air-introducing path 17 is defined by rear parts of the upper and lower casing 1 and 2.
The frame 4 is provided at its opposite ends with elastic hooks 11 and 11' projecting upward, which are to be engaged with the shoulders 9 and 9' of the upper casing 1, respectively. The frame 4 is also provided with a pair of guide rods 12 and 12' having predetermined length and projecting upward at its upper surface and between the hooks 11 and 11'. The guide rods 12 and 12' are inserted in the compression coil springs 7 and 7'. The upper plate of the frame 4 is formed with a semicircular recess 13 at a middle portion of its front end. The frame 4 has a lower plate 14 for sustaining the duster 3.
The support plate 5 is provided with a central boss 15, which is inserted in the semicircular recess 13. The central boss 15 is formed with a screw hole 16 at its upper end so that the support plate 5 is mounted on the lower surface of the upper casing 1 by means of the screw 6. Also, the central boss 15 is inserted in the compression coil spring 7".
In use of the above-constructed nozzle head for a vacuum cleaner, the frame 4 which is assembled with the support plate 5 is moved downward and then the support plate 5 is mounted on the upper casing 1 in such a manner that the screw 6 is engaged with the upper casing 1 through the screw hole 16 of the central boss 15. Subsequently, the duster 3 is put lo between the support plate 5 and the lower plate 14 of the frame 4 and the frame 4 is pushed upward. At this time, since the compression coil spring 7" is compressed, the support plate 5 is moved downward due to the compressive force of the coil spring 7" so that the duster 3 is firmly fixed between the support plate 5 and the lower plate 14.
Thereafter, as the frame 4 is further pushed upward, the compression coil springs 7 and 7' are compressed and the elastic hooks 11 and 11' of the frame 4 are engaged with the corresponding shoulders 9 and 9' of the upper casing 1, as illustrated in FIG. 2, so that the duster 3 is more firmly fixed between the support plate 5 and the lower plate 14.
On the other hand, when it is necessary to separate the duster 3 from the nozzle head, the elastic hooks 11 and 11' of the frame 4 are pushed inward or toward each other to disengage the hooks 11 and 11' from the shoulders 9 and 9'. Then, since the locked condition of the frame 4 and the support plate 5 is released because of the restoring force of the compression coil springs 7, 7' and 7", the duster 3 can be separated from the nozzle head.
However, the above-mentioned conventional nozzle head for a vacuum cleaner has disadvantages as follows:
Since the conventional nozzle head for a vacuum cleaner employs a flat duster, a contact surface of the duster which is in contact with a floor is limited in its lower surface so that the duster is easily contaminated, thereby decreasing cleaning efficiency.
Also, when the duster is changed with a fresh duster, the frame and the support plate must be fully disassembled from the nozzle head and assembled.
Furthermore, since what actually supports the duster is the central compression coil spring inserted in the boss of the support plate, when the elasticity of the compression coil spring is deteriorated by use over a long period of time, the duster may be accidentally separated from the nozzle head because the duster can not overcome a frictional force with a floor.